Opponents of a referendum to build a $160 million aquarium on the City Hall property announced Friday they have formed a political action committee to persuade voters to reject the proposal. A pro-aquarium PAC formed months ago and will formally plan its campaign next week.

The groups plan on making cases to community groups and putting up yard signs. City leaders say they welcome the debate.

“I assumed there would be (groups for and against it),” said Clearwater Mayor George Cretekos. “That’s just standard operating procedure.”

Voters will decide Nov. 5 whether to let the city lease the City Hall property and some nearby parkland to the aquarium, which would pay the city $7.5 million, plus interest, to build a new city hall, as well as $250,000 a year after that. Its current building, which was fashioned from an old sewage treatment plant, would remain open as a hospital for injured sea turtles, dolphins and other marine life.

The aquarium has seen a spike in attendance since the 2011 release of “Dolphin Tale,” the film featuring Winter, the dolphin with a prosthetic tail that lives there. Aquarium officials expect another surge with the release of a sequel next year. Supporters say the increase in aquarium traffic would spur development in a downtown Clearwater.

“There’s been multiple efforts over, really, decades to get a good, healthy, long-lasting spark in downtown Clearwater,” said Nick DiCeglie, who chairs the board of the Friends of the Clearwater Marine Aquarium PAC.

DiCeglie, who also chairs the Clearwater Regional Chamber of Commerce board of directors, and said the business community generally supports the concept.

“We’ve really worked hard to create a business-friendly environment there. It just really hasn’t had a spark.”

Critics say a tourism-centered redevelopment strategy won’t create a renaissance in the area.

“You need to develop it for the residents,” said Joe Cordiva, an activist with Friends of Clearwater, the antiaquarium PAC. “Cleveland Street will never succeed if it tries to be like Mandalay [Avenue].”

Opponents also say the aquarium is inflating its ticket sales projections and that the city would be handing over public land if the referendum passes.

“We started looking at the numbers and looking at the actual referendum, and we thought, geez, the city is really giving away the property next door for pretty much next to nothing,” said Sarah Donovan, who heads Friends of Clearwater.

Donovan and Cordiva both live nearby, but she said say their sentiment is shared among residents throughout the city.

Among their concerns is increased traffic in the area and that the city might have to pay if annual attendance numbers drop well below one million.

“If the aquarium does not take off the citizens of Clearwater are going to have to pay for it,” Donovan said.

The group is taking cues from an effort to kill the Lens project in St. Petersburg. That issue comes to a vote at the end of this month, and opposition to that project, intended to replace the aging inverted pyramid pier, is strong.

“We’ve been following what [they] have done,” she said. “Their effort has been fantastic and has had a lot of volunteers. I think more people became aware and started to look at the issues.”

The aquarium’s proponents say they expected an opposition group to form and say attendance numbers, while not easy to project, were not inflated.

“First of all, it’s very difficult to get an exact number on project attendance,” DiCeglie said. “We can’t forget that we’ve got a sequel that’s [filming] here in the fall. If we couldn’t get a sequel, we’d be having a much different conversation today.”

Aquarium director David Yates said he hadn’t heard about the PAC yet Friday and didn’t know who any of its members were. But he did object to the claim that the facility will cost taxpayers, saying it would indeed benefit the city as its downtown redevelops.

“There are no new taxes being suggested, requested or offered,” he said. “Quite the contrary.”